Harry p



(No Model.)

H. P. DAVIS.

ELECTRIC ARG LAMP.

No. 569,818. Patented ont. 20, v1896.

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UNITED STATES ATENTy i OFFICE.

HARRY P. DAVIS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE VVESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, OF

SAME PLACE.

ELECTRIC-'ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 569,818, dated October 20, 1896. Application filed January 14, 1895. Serial No. 534,830. (No model.)

To (LZ whom. it 71mm/ concern.'

Be it known that I, HARRY P. Davis, a citizen of the United States, residing in Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvementin ArcLamps,V (Case No.

624,) of which the following is a specification.

My invention relates to arc-lamps, and more particularly to methods of and means for controlling the feed of the carbons of such lam ps; and it has for its object to provide a means for and method of controlling the feed of arc-lamp carbons which shall automatically and effectively operate to exactly compensate for the consumption of the carbons, and thus insure the production of a light which shall be free from liuctuations and of uniform brilliancy.

The means heretofore most commonly employed for controlling the feeding mechanism of arc-lamps comprised a series-connected coil, which actuated a core or armature for separating the carbons thenecessary distance for producing the d esired arc and for maintaining such position of the carbons, and a shuntconnected coil for setting the feeding mechanism in operation whenever the separation of the carbons became too great. The objection to such means has been that the feed of the movable carbon was likely to be in excess of that required, the result being that the carbon-points were brought too near together, thus causinga iiuctuation in. the light, which was objectionable. It is the purpose of my present invention to overcome this objection by insuring a very slight movement of the feeding mechanism at each operation of the same, the operation being repeated until the desired amount of feeding is effected, any excess or overfeeding being thus prevented.

In Figure 1 of the accompanying drawings I have shown a side elevation of my feednegulating mechanism and the supporting-frame therefor, part of the frame being broken away in order to show the regulating mechanism more clearly. Fig. 2 is a diagram showing a modified arrangement of controllingcoils- Referring to Fig. 1 of the drawings, l is the supporting-frame, and 2 and 3 the lamp-carbons, the carbon 2 in the present instance being movable and supported by the usual metal bar or rod 4, having the rack-teeth 5 at one edge thereof. Pivotally supported in the frame at 6 is the frame 7, carrying the usual train of gears 8 9 10, the escapementwheel 11, and the escapement-lever 12. Supported from one end of the pivoted frame 7 is a dash-pot cylinder l2, the dash-pot piston 14 being pivoted to the frame 1. Connected to the frame 7 at the same side of its pivotal support 6 is one end of a coiled spring 15, the other end of the spring being attached to a nut 16, mounted on a screw 17, fixed to the base of the frame 1. Pivotally supported from the other end of the frame 7 is a core 18, and surrounding the lower end of this core is the coil 19, in series with the lampcircuit.

Surrounding the upper end of the core 1S is a shunt-connected coil consisting of two reversely-wound sections 2O and 2l. Bearing against one side of the carbon-supporting rod 4 is a brush 22, connected by means of a conductor 23 to any desired part of the frame 7 or the feed-regulating mechanism carried thereby. As shown in the drawings, this conductor 28 is connected to the supporting-pivot of the escapement-lever 12. Pivoted to the frame 1, above the movable frame 7, is a stop-bar or lever 24, carrying at its outer end a head 25, an insulating-washer 26 being interposed between this head and its supporting-lever 24. This head 25,Which is located in the path of movement of the escapement-lever 12, is connected by means of a conductor 27 to the shunt-coil, the connection being made at the points 28 at which the reversal in winding occurs.

The operation of the invention is as follows: The current entering the lamp, asindicated by the arrows 29, passes through the carbon-supporting rod 4 and the carbons 2 and 3 and series coil 19. The latter draws down the core 18 and the corresponding end of the arm 7, thus elevating the other end of said frame, separating the carbons,and bringing the escapement-lever 12 into engagement carbons has becom e sufficiently great to shunt IOO a portion of the current, it will be seen that the portion 2l ol the shunt-coil will be shortcircuited, the portion 2O only being energized. rlhis energized portion of the coil will serve to raise the core 18 and thus move the escapement-lever l away from the stop-head 535 suflicientlyto permit a slight movement of the feeding mechanism. rlhe separation of the parts 12 and 25, however, opens the short circuit and current passes by conductor 30 through both sections of the shunt-coil. The section 2l being wound in a reverse direction to that of section 20, the pull of the latter upon the core 18 is opposed by the action ci' the former, and the frame 7 is rocked to bring the parts 12 anc 25 again into engagement, thus locking the escapement of the 'feedingtrain against further movement. Il the distance between the carbons is still in excess of normal working conditions, the operation just described will be repeated until the movable carbon has been 'fed the required amount.

In the modiication illustrated in Fig. 2 the normally short-circuited portion 2l of the shunt-coil is located adjacent to the series coil 19 in order to exert a pull in opposition to that of the portion 20' when the short circuit is interrupted. It will be readily seen that the result effected is the same as when the arrangement of coils is that shown in Fig. 1.

It will be readily understood from the de scription of the apparatus heretofore given that the tension ol the spring 15 will be so regulated by means of nut 1G and screw 17 as to slightly overbalance the core 1S when no current is flowing through the lamp. lt will also be understood that the dash-pot acts as a retardin means to insure the necessary gradual and regular movement of the frame 7, its operation being in no way different in this connection 'from that of such devices as ordinarily used.

\Vhile I have described specific regulating mechanism, I desire it to be understood that the controlling means described are applicable to other forms of mechanism, and I do not desire to be limited to the specific form shown and described. It will also be understood that the series and shunt spools may occupy different relative positions in the lamp from those shown and described and that a separate core for each coil may be emphnyml, if desired.

I claim as my invention- 1. The combination with a series coil and a shunt-coil having two sections, one oi' which is normally short-circuited, ol.` a rocking frame provided at one end with a movable armature or core common to said coils, and a spring and a movement-retarding device connected with the other end of said trame, substantially as described.

2. The combination with a series coil and a shunt-coil having two sections, one of which is normally short-circ uited,oll a workin g frame provided at one end with a movable armature or core common to said coils, and a spring and a movement-retarding device connected with the other end o1` said ['rame, substantially as described.

3. The combination with the htmp-l'rame, of the pivoted frame andthe gear and escape ment mechanism carried thereby, a core or armature and balancing means therelm', a series coil, a shunt-coil having two sections and an insulated stop in the path of movement of the escapement and having a single connection to the two sections of the shunt coil, substantially as described.

4. The combination with carbon-feed-regu lating mechanism, of a series coil, two shuntcoil sections, a core or armz'tture con'nnon to said coils and connections whereby one ol said shunt-coil sections is short-circuited when the core is actuated by the series coil, substantially as described.

5. The combination with the pivoted tranny. and the feed-regulating mechanism carried thereby, of a movement-retarding device and a solenoid-core, attached to opposite ends ol' said frame, a series coil and two shunt-coil sec tions common to said core and means whereby one of said shunt-coil sections is short-circnited when the core is actuated by the series coil, substantially as described.

In testimony whereof I have hereunto subscribed my name this 10th day ol January, A. D. 1895.

HARRY I. l AVIS.

lVitnesses:

WESLEY G. GARR, HUBERT C. TENER. 

